Did NASA accidentally invent a warp drive?

Daniel and Jorge dissect research articles claiming sudden progress in warp technology

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Episode Transcript

Speaker 1 (00:08):
Hey, Daniel, what's your first reaction when you see a
dramatic science headline? M M, I guess it's a superposition
of excitement and skepticism. The quantum reaction. What do you
mean by skepticism is part of you assume the study
is not real? No, it's more skepticism because I think
the news coverage might not be fair. Wait what he's saying?

(00:31):
The news media is biased. I get this constant stream
of articles sent to me by listeners who asked me like,
is this for real? Can I believe this headline? But
somehow I believe you. Well, I think we've earned more
trust than some of those websites called like coffee or
die dot com or link zilla dot org. I've never
been to those sites, but thanks for the reference. I'm

(00:51):
always looking for ways that Icetein was wrong. I hear
there are ten reasons you won't believe the seventh one.

(01:12):
Hi am more handy cartoonists and the creator of PhD comments. Hi,
I'm Daniel. I'm a particle physicist and a professor at
UC Irvine, and I'm dying to find out why Einstein
was wrong. You're dying to find out you would give
up your life find out why Einstein was wrong. I
guess it's more figuratively dying to find out. But I
do get a lot of emails from people who say

(01:32):
they have figured out how Einstein was wrong, and every
time inside me there's this little flash of hope. Maybe
this is the person who has figured it out. Yeah,
you never know, right, I mean, Einstein was just some
dude working in a pen office, and he figured out
that everybody else was wrong. Einstein was a very smart dude.
But yes, you're right, he was just a human being
with a human brain thinking about the way the world

(01:54):
works and coming up with a more beautiful and more
compact and more effective description of reality. But we're also
pretty sure his ideas weren't the final ideas. So you
think he is wrong. I'm very sure that Einstein is wrong.
I just don't know who's right. So what do you
do with those emails? Do you a fact check them?
Do you go through them? Yeah? Absolutely, I read them.

(02:16):
I scan through them. I give them some feedback on
the science. Do you encourage them to submit it to
a journal or at least a coffee or died dot com.
Most of them aren't really in journal ready format yet,
so I give them some tips about how they might
get there. I see you give them a tech or
word processing tips. Welcome to our podcast Daniel and Jorge
Explain the Universe, a production of I Heart Radio in

(02:37):
which we try to figure out how Einstein was wrong
and also how he was right. Our goal is to
explore how the universe works, to wonder about all of
its crazy mysteries, those fundamental questions about the very nature
of reality, what rules all those particles are following. We
want to weave them all together into a deep and
beautiful understanding of this cosmos, and we want to explain

(03:01):
all of it to you. That's right. It is a
vast universe full of mysteries, and our understanding of these
mysteries is constantly changing. Science is not a constant thing,
and science is not done, still working hard to figure
out how things actually work, because the way we think
it might be working doesn't always pin up. That's right,
and it also doesn't make progress in a steady fashion.

(03:21):
It's not like every day we get five more units
of science. There are moments in the history of science
when somebody has a flash of insight, when years of
struggle finally coalesced into some progress and we make a
great leap forward in our understanding. And you never know
what day is going to be one of those days. Yeah,
everybody tunes into the science news of the day to

(03:43):
see if a great new discovery has been made, or
if scientists figure out how to do some amazing thing,
or if it's just linzila dot org spamming us again,
giving us clickbait. But there are always interesting news headlines,
sometimes on the on the regular news, and sometimes they
spill over onto the mainstream media, right, Yeah, And sometimes
they seem like click bait, but they are real. You know,

(04:06):
scientists measure gravitational waves, ripples in the fabric of reality.
That sounds like it was made up by a copy
editor working in a basement somewhere, but that was real. Yeah.
Science does make a lot of progress, and people are
excited when something really big happens. But sometimes those headlines
are a little bit overblown. That's right. You can't believe
everything you read in all of the popular media about

(04:28):
scientific progress. Sometimes they're just trying to get you excited
and make you click on their link. We had a
whole episode about how to critically read popular science articles,
the upshot of which was develop a few sources of
information that you really trust and check those Wait, wait,
are you trying to tell people that you're the only
person they can trust? Is that what it is? Isn't

(04:51):
that how how cults work? I do think we are
a pretty reliable and even handed source of information about
science progress. But there are other places you you can
get your science news. I like the coverage in the
New York Times and in the l A Times, and
also in Quantum Magazine, often very insightful and always very
well informed, but also false and non informed at the

(05:12):
same time. Because it is a quantum magazine, they try
to deliver one quantum of understanding at a time. But
there's a lot of information and news out there, and
it's kind of like you say, it's hard to figure
out what is real and what is not, or maybe
what is real but exaggerated. I think that's maybe a
lot of what happens in these news headlines, right, there's
like some neggat of truth, but they sort of emphasized

(05:32):
the extreme interpretation of these things. Yeah, often they have
removed the coffee AATs and the qualifiers, and so you know,
somebody does like a simulation of a black hole universe
on their computer one afternoon and writes a paper about it,
and then the news headline is like graduate student plunges
entire universe into a black hole or something similar. Well,

(05:54):
that's probably only exciting for that gratitude. Well, you have
a whole ted talk once. I think about the scientific
news cycle and how this happens, how real scientific research
gets sort of filtered and amplified. Yeah, and then how
it all comes back to your grandma and how she
ends up wearing tinfoil hat. So we do think it's
very important that everybody out there have a sense for

(06:15):
what's real and what's exaggerated. So when a bunch of
listeners all send me the same article, I think maybe
it's sound to do an episode about one particular piece
of research. Yeah, and then months later the episode comes out.
Sometimes we rush it right. Sometimes we if it's a
hot topic, we'll ask my hard to put it out quickly.
That's right. We do sometimes try to be responsive to
the real world. And so recently there's been a pretty

(06:37):
incredible sounding headline that a lot of people wrote to
you about. Right. I guess people look to you to
know if something is overblown or real, because I'm certainly
not getting those emails. How do you know? Are you
reading your emails these days? But every morning in my
inbox I certainly get a pile of email from listeners
who say I saw this headline? Is this real? Or
could you do an episode explaining this to me? Because

(06:58):
I still don't understand it. Yeah. Pretty recently there's been
a pretty exciting sounding headline about warp drives and NASA.
To the question we'll be technic today is did NASA
just accidentally build a warp drive? Nathaniel? Which part is

(07:19):
maybe not real? The accidental part? Did they build one
on purpose? Actually, let's see the parts about this headline.
They're not real, are the NASA part, the accidental part,
and the warp drive part? So they did build something?
Did build something? No, they didn't even actually build. So
let's see which works are left here? Um might have

(07:41):
did something? Might have happened. So I'm looking at a
web page from Coffee or Die dot com and the
headline is DARBA and NASA scientists accidentally create warp bubble
for interstellar travel. There's no might or maybe, Well, we'll
dig into this headline, but first, we were wondering how
many people out there had her about this or think

(08:01):
it's real. So thank very much to everybody who volunteers
to answer these questions for this section of the podcast.
We really appreciate you speculating about things you haven't had
a chance to prepare for, and hope everybody else out
there enjoys them. If you would like to participate for
future episodes, please don't be right to me. Two questions
at Daniel and Jorge dot com. So think about it

(08:22):
for a second. Do you think Naha just accidentally or
on purpose build a warp drive? Here's what people had
to say. I'm pretty sure they did not discover a
warp drive, only because that would be pretty big news,
and as far as I know, I've heard nothing about it,
so I'm gonna say no, No, they definitely did not
accidentally discover a warp drive. I would love that to

(08:43):
be true, but I'm pretty sure that's not the case.
Since you're asking, I think the answer is yes, but
I haven't heard about it. I don't think that's I
can do mistakes like this, at least not now, probably
in the future. But I don't think this accident just happened.
I don't know, but I kind of hope so, because

(09:03):
I think that would be amazing to be able to
travel really far, really fast. All Right, a lot of
excitement and either way, people are like, I don't know,
but that sounds awesome. Yeah, just like me. Everybody wants
this to be true. And I think that's one of
the reasons that these articles are successful is that it
touches the excitement inside people. People are hopeful for this
kind of leap forward in technology. Yeah, I mean, I

(09:25):
guess at least the people who read Science News probably
also are fans of Star Trek, and so that that's
where kind of maybe the idea of warp drives first
god spread into the popular culture, and so people are
excited for this to happen because a lot of exciting
things happen in Star Trek. You think people are more
excited about warp drives or like the holidack. Well, the
holiday already exists, Daniel. You have a holidack. It's called

(09:48):
the metaverse. Well, that's right, and we recently took a
trip to the metaverse, so we should know all about it. Yeah,
it's nice and cozy there, But war drivece would be
pretty amazing, right, because they would let us travel to
other stars and their planets and maybe other galaxies. It
would be really incredible because one of the disappointing things
about the universe is that it's so big that everything
is so far away. We're limited to travel slower than

(10:11):
the speed of light, which seems really fast, but even
in comparison to the vast distances between stars or between galaxies,
it's not really fast enough to get us interesting places
in the reasonable amounts of time. So a warp drive
would be a wonderful way to like zip around the
galaxy or the universe and just learn so much about
what's going on out there. That would be super cool.

(10:32):
Although Daniel, I feel like you shouldn't be disappointed at
the universe for for being so big. That feels a
little mean, you know, like maybe it's our fault for
not being fast enough or big enough. Yeah, maybe disappointed
is too judgmental. I'm just frustrated. I feel like there's
information out there. You know, there are either aliens living
on other planets and crawling around of those services or not,
and the facts are out there. They either are or

(10:54):
they aren't, and we could know it if we could
just like get there and see these things. But everything
is so rustratingly distant. It's like somebody has answers to
the deepest questions about the universe, but they're keeping them
in a locked box and you can't see them. Yeah,
unless you go to coffee or die dot com. They
seemply have the key. It would be pretty cool, and
it is pretty prevalent in science fiction movies warp drives

(11:16):
because I guess it solves pretty much any plot that
the problem that you might have in setting up a
space story, right, because without a warp drive, you pretty
much can't have any space stories because it would just
take too long to get between planets or between parts
of the galaxy. What's an interesting question with a few nuances.
I mean, in one hand, you can't realistically have like

(11:36):
a galactic empire. You can't make decisions for a set
of stars that are many, many light years apart, because
when you make a decision, it takes like years and
years even for that information to propagate across the galaxy.
Or how can you like move your army from one
star to another, or gather resources in one place and
move them somewhere else. It really effectively limits you to

(11:58):
operating in a single soul or system. Yeah, Like even
just to send an email to the other side of
the galaxy would take a hundred thousand years, right, that's right,
So you can't really coordinate across different parts of the
galaxy due to the speed limit of the speed of light.
But you know, if you're patient, you could send out
explorational teams which could discover those other star systems, so

(12:18):
you could realistically still have like first contact stories, but
you can't zip back and forth between stars that are
really far apart. I wonder if it just maybe our
point of view about time, Like if we live to
be a million years old, you know, maybe a hundred
thousand years old to send an email wouldn't be that bad. Yeah,
that's a really good way of thinking about it. The
speed of light really is a relationship between time and distance,

(12:41):
And so if time isn't much of an issue for
you because you're gonna live to be a million years old,
then the universe is a lot more local than if
you live very short lives like we do. Well, regardless
of how old you live, having a war drive would
be pretty handy for exploring the universe. For sending emails
to the other side of the galaxy. And this headline
that people are sending and you seems to say that

(13:01):
NASA may have accidentally build a warp drive. I wonder
wh where the accidentally comes from. Are we going to
cover that. We are going to cover that. Absolutely yes.
So it's a pretty tantalizing headline. And so let's dig
into this idea first of all, and let's start with
the basics. Daniel, what is the technical definition of a
warp drive? So a warp drive sounds like science fiction

(13:21):
because we hear about it in science fiction, and usually
you hear scientists saying that it's impossible that you can't
go faster than the speed of light. And so a
warp drive just sounds like, you say, a science fiction
plot saver a way to just like dot dot dot
your way to distant stars without worrying about the limitations
of the speed of light. But in the last few decades,
there has been a lot of progress in imagining how

(13:44):
we might build a warp drive using actual science, using
real technology. It's not like we have plans for a
warp drive right now, but we have sort of a
direction that theoretical physics points as towards that suggests it
might be possible. What are you saying that NASA has
accident proven that warp drives are possible. I'm saying that
we're like step one out of three million towards building

(14:05):
a warp drive. Are you saying that NASA has taken
the first steps towards building a war drive? There are
some theoretical physicists that have laid the foundation, yes, which
may eventually lead to actual warp drives being constructed. What
are you saying that that's I will eventually build a
war drive. I think you've had too much coffee or
die this morning. No, I'm just kidding. Let's maybe be
super clear about this, right, this is an idea where

(14:28):
you have something aboard your spaceship, right, and this device
that you have on your spaceship somehow, let's you cut
through space, right, or go faster than the speed of light.
That's the idea of warp drives, right, Because it's maybe
different than like the warmhole gate that some science fitch
and stories used to go between spots in the galaxy. Yes,
so you do have to follow the rules of relativity.
And the cool thing about the warp drive is that

(14:49):
it does follow the rules of relativity. We're used to
relativity telling us that you can't move through space faster
than light, and that doesn't change. We can't avoid that.
But relativity also tells us that space isn't just flat,
that it can do weird things, that the relative distances
between points in space can change. When we talk about
space curving or bending, that's really what we mean. We're

(15:12):
changing the relative distances between points. Remember that space isn't
like relative to some external rulers, So when we talk
about the distances between things, these are really just intrinsic
bending of space. You often see this rubber sheet analogy
where somebody puts like a bowling ball on a rubber
sheet and it bends the rubber sheet. That's helpful for
thinking about bending, but it's also quite misleading because in

(15:33):
that example, the rubber sheet is bending in relation to
some third external dimension. Here, were really just talking about
changing the relative distances between points in space, and that's
something that we know can happen. That's something that we
have observed. We see it happen in gravitational waves, which
are ripples in space. We see it happen in gravitational waves,
which are ripples in space. We see it happening in

(15:55):
the expansion of the universe, which is increasing the relative
distance between it's in space. So there was a guy
named al qb Air a few decades ago who came
up with a sort of arrangement of space that would
allow you to move like a chunk of space relative
to other bits of space to sort of like create
a warp bubble which would itself move relative to space.

(16:17):
So you could sit inside that warp bubble and it
would transport you to your destination. Yeah, there's this idea.
I guess that space is not like empty and immovable
and fixed and super stiff or or rigid, but space
is kind of squishy, right, like for example, black hole
sort of squishes the space around self, bending space and
maybe creating some weird kind of shortcuts through space. Yeah.

(16:40):
Einstein's big idea was that the whole concept of gravity
is not a force the way Newton imagined it. It
was just that things move in response to the shape
of space. That space has a shape, it's not just flat.
And so because we can't see that shape directly, like
you can't look at space and say, oh, I see
that it's curved, but we can see how space changes
the motion of things that go through it. We discover

(17:03):
that gravity is just like an apparent force. It looks
like there's a force on stuff, but it's really just
stuff moving through curved space. And you can do much
more than just curve so that the Earth goes in
a circle around the Sun, for example. It can ripple
like gravitational waves, and it can expand like dark energy,
and it maybe even more amazing things like warp drives
and wormholes. Yeah, you're saying that scientists in recent years

(17:24):
have taken these ideas about relativity and figure out maybe
a way that you can make a warp drive using relativity.
And it's specifically something called a war bubble that might
let us use it to actually get to other places
in the galaxy or even the whole universe. And so
let's get into the details of this warp bubble. But
first let's take a quick break or I we're talking

(17:58):
about the headline NASA accidentally build a warp drive part
of Yes, you know you are giving too much credit
to this headline. It's not asking the question did NASA,
It says NASA scientists accidentally create war bubble for interstellar travel.
What did they say might have or did they actually
did it? It says they created it. That's what the

(18:18):
headline says. Well, we are digging into this headline to
see if it's true or not. And we've talked a
little bit about what a war drive would look like
and what it would be, and it sounds like so
far scientists have only come up with one possibility for
making a warp drive, and that is to make a
war bubble. And it's based on a special concept you
were talking about. Yes, So a few decades ago, there

(18:40):
was a gravitational theorist, Miguel al Kubier, who said, what
if you could bend space in a very particular way,
And so he took a spaceship and he bent space
around that spaceship so that the space around the ship
itself was flat, but then there was a bubble around
the ship that moved that flat space through space is itself.

(19:01):
So it's like you take a chunk of space and
you sort of slide it through other space and so
that you can just sort of sit inside that bubble
and then you get to your destination and inside the bubble,
you don't feel like crazy acceleration or anything. It just
feels like you're sort of floating there. So his question was, like,
what shape of space do we need in order to

(19:22):
accomplish that? And the cool thing was that he figured
one out. He figured out a way to be consistent
with Einstein's equations and also compress space in front of
this bubble and expands space behind the bubble, so the
bubble effectively moves relative to the rest of space. Yeah,
I know we've covered this in our book, maybe both books.
We can. We ask questions about the universe and we

(19:42):
have no idea and this, I have to say, this
always kind of puzzled me a little bit. So maybe
let's step people through it. So the day is that
you're on your spaceship during space and you flip the
switch or you pull the lever forward on your warp
drive device, and what it's doing, you're saying, is that
it compresses this space in front of you and it
expands the space behind you, and somehow that moves you

(20:05):
through space faster than the speed of light. Remember when
we say compressed or expand we're not like making space
more dense or anything. What we're doing is changing the
relative distances between points. That's what general relativity in Einstein's
equations do. They start from a certain distribution of matter
and energy, and they say, if you have a blob
of stuff here and a blob of stuff there, how
will space curve? What are the relative distances between any

(20:27):
two points? So that's called the metric. The solution to
Einstein's equations is the metric, which is just another word
for like how to space curve, or another way to
think about like the relative distances between two points. So
Alcubier's warp bubble says, is there a way to shrink
distances in front of this warp bubble and expand distances
behind it? Okay, so let's say I'm in my spaceship,

(20:48):
I'm orbiting the Earth, and let's say you just want
to take a short hop over to Jupiter. So I
engage my warp drive, I pushed the lever forward, I
put on my seat belt, and suddenly the space in
front of me between me and Jupiter, instead of being
millions of miles, suddenly it's three miles. Is that what
you're saying, Like, somehow I am affecting the space between

(21:08):
me and Jupiter, so that what used to be billions
of miles is now just a few miles. Is that
the idea? That's the idea, and that only works for
me or for anyone like caught in the middle or
anyone who hops in behind me. Do you know what
I mean? Am I just affecting the space relative to
me as an observer? Or am I actually affecting the

(21:29):
space between here and Jupiter? So it works for anybody
within the war bubble. It creates this sphere around the spaceship,
and that sphere then gets slid along through space, so
it sort of gets moved, so it gets rearranged. Its
relationship to the rest of space changes, right, It's now
closer to Jupiter and further from Earth, and so anything

(21:51):
inside that war bubble has the same experience. Does that
mean that the bubble needs to encompass Jupiter? Or am
I just compressing the distance between here and the edge
of the bubble? Inside the bubble, everybody hangs out and
SIPs their coffee. The bubble's edge is where space is
being compressed, So between the bubble and Jupiter space is
being compressed, that distance is being shortened, and between the

(22:14):
other edge of the bubble which is sort of behind you,
that space is being expanded. What if there's something right
in front of me outside of the bubble, but between
me and Jupiter, Like let's say there's a satellite there
or an old Grammar crossing this interstellar street, Like, what
happens to that person in between? Did they get squished
or do they not even see this, this bending of

(22:35):
space that's happening to me or to my bubble? Yeah,
this would be bad news for space Gramma for sure.
I mean this is very destructive changing of the shape
of space. Basically, anywhere between your warp bubble and Jupiter
and the same thing between you and behind what get squished?
It would get squished absolutely. Oh so between so I
mean a bubble, let's say invent bubble is the spaceship.

(22:57):
So anything inside the specip is normal, anything outside gets
bent around, and so the space between the spaceship and
Jupiter gets compressed. And but then wouldn't that affect the
other planets as well? You're saying anything caught in the
middle will get squished, But would it affect like the
orbits of planets and everything else in the near vicinity
of your ship? It certainly does affect things. So things
in your path definitely do get affected, So you know

(23:20):
warnings to all the space. Grandma's out there taking a walk,
and anything very close by is going to get affected.
But the shape of the work bubble is quite tight,
so it doesn't like affect the gravity of things very
far away. Well, let's get into what would happen to
Grandma she gets like squished flat or or what or
would she even noticed because you know, she's spaces just
changing her runner and so her molecules also change space.

(23:42):
Grandma would be very unlikely to survive this encounter because
the space she's in its metric would be changing, and
so that's likely to tear her apart. Changes in the
shape of space can have an effect on the objects
in that space. That's how, for example, we discover gravitational waves.
We see that space is shaking a little bit, changes
the relative distance, for example, between mirrors that are hanging

(24:02):
underground miles apart, and so you probably don't want that
to happen to your space. It's happening all the time
right now. Space is expanding out from under us because
of dark energy, but it's very very gentle, and our
molecules are powerful enough to hold ourselves together. If that
was much more rapid, then you would get torn apart.
And so that's what's going to be happening behind the

(24:23):
work bubble, and the opposite is what's happening in front
of the warp bubble. So yes, that will be quite destructive.
I guess that's why you need crosswalks even in space.
So then the space in front of me between here
and Jupiter suddenly goes from a few million miles to
two miles. And then you're saying the space behind me.
You know, I was an orbit around Earth, but now
suddenly the space behind me, me and Earth goes from

(24:44):
a few miles to a few million miles. Is that
the idea? Exactly? And that's basically travel, right. You've gone
from far away from Jupiter too close to Jupiter. Yeah,
But then I guess what's the next step. Do I
then move the few miles and suddenly I'm in Jupiter?
Or do I just turn it off and suddenly I'm there? Yeah,
you just turn it off. I mean your goal was
to get close to Jupiter, right, So you've rearranged space
and now you're close to Jupiter, right, you're two miles

(25:05):
from Jupiter and two million miles from Earth instead of
the opposite. It is weird because I compressed space in
front of me, but don't I need to expand it again.
Remember that compressing space is changing the relative distance, right,
So that is already accomplishing your goal. Right. Your goal
is I want to be close to Jupiter and far
from Earth. And so that's what the war bubble has

(25:26):
done for you. It's rearrange space so that now you
are close to Jupiter and far from Earth. It feels
kind of like magic, like you just said, like, hey,
I want to be there, so you're there. It's not
exactly magic, but it's also not exactly science yet. I Mean,
what al Kubire did was just say, is there a
way to arrange space in a manner that still is
a solution to Einstein's equations? Like do Einstein's equations prohibit

(25:50):
this from happening? And the answer is no. What he
didn't do is figure out how to make it happen.
Like Einstein's equations go in one direction, they say, if
you have this arrangement of mass and stuff in universe,
what is the shape of space around it? Cool? And
then how does things move in that space? What they
don't do is tell you, if you want a certain
shape of space, how do you build it? And so

(26:11):
Alcubier just said, well, is it possible to have this
shape of space? And Einstein's equations say yes, that would
satisfy the equations, But it doesn't tell you how to
arrange stuff in the universe to make space do that.
That might be impossible, And in Alcubier's paper he discovers
that the only way he could come up with to
make this happen was to have some weird kind of
matter that has negative mass or negative energy density, which

(26:35):
as far as we know, doesn't exist in the universe.
I see you're saying, Einstein's equations what we know to
be true. We know it works, but it doesn't tell
us that we can't do magic. Basic like, it tells
you that it's possible to be here close to Earth,
and it's also possible to be there close to Jupiter. Uh.
And so technically you might be able to figure out
a way to make those two things sequential in time

(26:59):
very quickly. Yeah, And it's a little bit more than that, right.
He did show that it doesn't violate Einstein's equations, which
means space says, sure, I can do that if you
assemble mass and energy in the right configuration to make
me do that. I won't tell you how to arrange it, right,
I won't tell you what the recipe is. But in principle,
let's not off the table. So that's like a big

(27:20):
hole in the argument. We don't know how to build
this thing, but the universe's list of rules don't explicitly
prohibit it. But what does the recipe? What does it
actually say? You're saying it needs like negative energy or
negative mass, And then what do I do that? Do
I just put it in front of me? Do I
need to lay it out between here and Jupiter? Do
I need to you know, spit it out in front
of me? You know? And like what does it say

(27:42):
about how to use this or how you would need
to use this negative energy? So since the original paper,
there's been a proliferation of really cool ideas about how
to do this and how to do it more efficiently.
So far, every solution, every paper I've read, requires using
some kind of negative energy density matter behind you in
order to expand space, and some sort of positive energy.

(28:04):
The entity matter of like normal matter like me and
you in front of you to compress space. So basically
you have to build a track of matter in front
of you that compresses the space, and then you have
to have negative matter behind you to expand the space.
So I do, I do have to lay out the
whole track, the whole highway for the world drive to work.

(28:24):
And you need to have positive energy mass in front
of you and negative energy mass behind you. All right.
We talked about this once on an episode about whether
you could use a warp drive to escape a black hole. Basically,
you have to build the track out of the black
hole first in order for this to work. All right,
So then I have to build a track. I guess
I would have to build it. But to build the track,
I have to get the Jupiter first. Yeah, exactly, Like

(28:47):
you know, to lay out a highway between here and Jupiter,
I have to go from your Jupiter exactly, huge caveat there. Right,
you have to build this track somehow. I mean it's
possible that somebody else could come up with another way
to make space do this that doesn't require you to
visit that place in advance and sort of be able
to track along the way. Remember that Einstein's equations just

(29:08):
say space can do that if you can figure out how,
And now people are trying to be creative about figuring
out how to do that, and so that's one obstacles,
like laying this track in front of you. The bigger
obstacle is that we've never seen anything with negative energy
density before. We don't even know if that's possible to
do in the universe. It sounds like it's more of
a like a warp train than a warp drive, right,

(29:31):
Like you kind of have to lay out the tracks
or are you gonna be like those cartoons where you're
like going and laying the tracks down at the same time.
Leave it to the engineers to figure out some way
to make this very effective. The physicists are just like, well,
space says we can do this if somehow we can
arrange a strange matter in the right configuration. Right. But
as as the engineer, I would be mad if you
told me like, hey, I can out with a way
to make a warp drive, but it's actually a warp train,

(29:53):
you know, and then then we brought all the wrong
tools to make it. You'd be disappointed in a warp train.
I'd still be pretty excited about warp train. I mean,
you're right, it's not a warp drive but a warp train.
It's still pretty awesome. Yeah, No, I think both. It
would be exciting. But you know, if I'm gonna pay
for a ticket, I want to know what I'm getting,
or if it's going to be a train ride or
it's gonna I'm gonna see some fancy star show. All right,

(30:15):
So then it seems like it's it is possible, at
least from a theoretical perspective, to make a warp something
warp driver or train or I don't know, tram. Perhaps
how about a warp zip line that would be pretty cool. Oh,
there you go. So it seems possible. But the question
is how you would make it. And there's this idea
of a Casimir effect that might be able to do it,

(30:36):
and that's kind of where where this headline all originated. Right,
So what exactly did this study that the headline is
based on do. This study is trying to make progress
on the stickiest part of the warp drive or warp
train project, which is negative energy density. Right. By energy
density would just mean like how much stuff is there
in a certain part of space. Matter has energy to it,

(30:57):
right equals mc squared, and so if there's a lab
of stuff in space, that's positive energy density. So the
warp drives needs something with negative energy density in order
to expand the space behind you. And so this project
was trying to figure out like, well, is it possible
to build things with negative energy density? And here's the
accidental part. They weren't actually trying to crack this problem

(31:17):
of the warp drive. They were just studying the Cassimir effect,
which is a well known and actual thing which we
have proven is real. And they were looking at the
energy density of the Cassimir effect and they noticed something
interesting to them, at least which they connected with warp drives.
I see. So this is now jumping off from this
idea of a warp train that you can compress space

(31:39):
and expanded behind you. But to expand the space behind
you you need negative energy. And so these folks were
studying negative energy and you're saying they found something, but
they did find something interesting, that's true. I mean, I've
read their paper. What they were doing is studying the
Cassimir effect, which is a really interesting and super awesome
quantum effect that appeared between two play that are very

(32:00):
very close together. So imagine two like two sheets of
metal and bring them like ten nanometers apart. What you
discover if you do that is that there's a force
between them. Even if they have like no electric charge
on them and we're ignoring gravity, you can measure this
force which appears between the plates because of this strange
quantum effect called the Cassimir effect. Okay, so what is this.

(32:23):
What's happening in the Casimir effect is that we're actually
interacting with and probing the vacuum energy of space. Remember
we've talked about how space is not just empty, it
is filled with quantum fields. Like there's a photon in
space that's a wiggle in the electromagnetic field. There's an
electron in space that's a wiggle in the electron field.
But even if you don't have a photon, and even
if you don't have an electron, space still has these

(32:45):
fields in them, these possibilities for particles to pass through them.
And because their quantum fields, they can never actually go
all the way down to zero energy. There's always a
little bit of fuzz, a little bit of energy. So
we call that the vacuum energy, the lowest possible energy
in the quantum field, which is not zero, And so
people wonder like, is that real, is it really happening

(33:05):
or is it just like part of our mathematics. Well,
the cool thing about the Casimir effect is that when
you bring these two plates really close together, it cancels
out some parts of those wiggles between these two sheets.
Only certain kinds of wiggles can survive, so it suppresses
some kinds of wiggles and allows others. And so because
it's suppressing some kinds of wiggles, it like lowers the

(33:26):
energy between these two sheets, which creates an energy differential,
which is what creates a force. So it squeezes these
two plates a little bit closer together because that's a
lower energy state. So the Casimir effect is like deleting
some vibrational modes of the quantum vacuum between these two
plates in a way that ends up pushing them together
a little bit. Right. It's sort of like you create

(33:47):
a space that is so small that most particles can
even fit in them, and so the universe can't create
those particles in that space, and so therefore it like
it creates almost like a void in space, right where
like nothing can happen there, So there's sort of like
an emptiness and the rest of the universe is biased

(34:07):
towards having a little bit of energy. Then that vacuum
somehow creates like a it sucks stuff in. Basically, it's
really fascinating because it lowers the energy of space there
below the vacuum energy. Right, typically we think the vacuum
energy is the lowest, but if you create this special configuration,
you can bring the energy of space below the vacuum energy,
as you say, prevents those fields from existing in certain modes,

(34:30):
and so it lowers the overall energy. You can either
think about this in terms of fields, if you like
thinking about space is filled with fields, or you can
think about in terms of virtual particles, which is really equivalent,
if you like thinking about space is filled with all
these virtual particles constantly popping in and out of existence.
Between these two plates, some kinds of virtual particles are
not allowed, and so the energy density is lower between

(34:53):
the plates. I see, so you're saying you're not creating
a spot of negative energy, You're just creating a spot
of lower energy. Then, like the normal amount of energy
that the universe has sort of like sound, right, Like
you can't have negative sound, but you can make a
room that's lower sound than like the average din of
the your space of your talent. Yeah, that's exactly right,
and some really important nuances there. As you say, it's

(35:16):
not really negative. Energy is just lower than the vacuum. Now,
if you define the vacuum to be zero, then it's
negative energy density, I suppose. But that's a little bit arbitrary,
just sort of like where you set your zero. Really
it's lower energy than the rest of space around it.
It's as an interesting puzzle there because all the physical
phenomena we observe this actual force from the Casimir effect.

(35:39):
This just relates to the energy difference, like the fact
that there's lower energy between the plates is what gets
the force. But if you try to do the calculations
and ask like, well how much energy is there in
the vacuum, you actually run into weird infinities like try
to calculate you say, well, there's an infinite number of
different possible modes in space, and so in principle there
should be infinite energy there, which gets really eared and

(36:00):
still nobody understands. So we see the Cassomir effect. We
know there's a lower energy density between the plates even
in the Casimir effect. We don't really understand what the
absolute energy is even in like normal empty space. We
just know that it's lower between the plates and the
Cassimir effect. All right, So we have this Casimir effect
that might be able to give us negative energy, which
might let us make a warp should you train? That's

(36:22):
how I think scientists you call. So let's get into
whether or not someone has actually made this Casimir effect
work and whether it can be applied to a warp drive.
But first, let's take another quick break. All right, we

(36:45):
are warping our way to examining news headlines, and particularly
a very specific headline recently that's that NASA might have
accidentally built the warp drive. And the study that created
this headline was actually looking at the Asimir effect, which
is a way to maybe create zero energy or negative
energy in the universe. Now, Daniel, this is a kind

(37:08):
of a theoretical effect, right, something scientists think it might
might happen if you run this experiment. Has anyone actually
done this and measured this negative energy? People have actually
measured the Cassimir effect, So Casimir predicted it in like
by doing a bunch of calculations, and it's a very
very small effect, so it took a long time and

(37:28):
some real virtuoso experiments. But in n Stephen Lamereaux at
Yale actually did this. He was able to measure the
force between two objects that really really close together and
found the forest was very close to what Casimir predicted,
and that's been verified since then. Yeah, there have been
other experiments that verified, and they've done it with various

(37:50):
different configurations. It's really hard to actually do it with
like two sheets that are like an animeters apart, so
instead they use like one sheet and a sphere for example. Experimentally,
it's just sort of easier to manipulate and at separations
of like ten nanometers, which is like a hundred times
the size of an atom, the Cassimir effect produces a
force about equivalent to like an atmosphere of pressure. So

(38:13):
you're saying we can create spots of negative or zero
energy in the universe, and does that mean then that
the space in that spot gets expanded like in an
award drive like it would do an a warp drive.
So we can create spots which have lower energy density
than normal empty space, right, and it does cause the
Casimir effect, and we've measured that and that's real. We

(38:35):
don't know if that actually means their negative energy density, right.
We don't know how to set the zero to try
to calculate the energy of all the space. You get
infinities which don't make sense, So we don't know how
to do those calculations. So an open question about the
Cassimir effect is what it means for gravity. Remember that
gravity is a classical theory. Einstein's theory of gravity doesn't

(38:56):
even know how to deal with particles, not to mention
like an infinite number of virtual particles. We don't actually
know how to calculate the impact of this kind of
arrangement on gravitational fields and on the shape of space.
We don't know the answer to your question of does
this expand the space between those two sheets? But I
guess in theory it is right because energy, in general

(39:16):
it compresses space. So you have something where a spot
where you have less energy than technically that space would
not compressed as much, which would be the same as
expanding space. It depends on whether the general relativistic concept
of energy density is the same as the quantum mechanical one.
Remember the quantum mechanical one. Here, we don't know if

(39:36):
this is negative or positive energy density, and we don't
know how to do those calculations because we don't have
a theory of quantum gravity. People have tried to do
those calculations and they get crazy predictions like oh, there's
infinite energy here, so you get singularities everywhere in the universe,
and so it's just sort of an open problem in
theoretical physics, sort of gravitational implications of the vacuum energy.

(39:57):
So you can create a spot of almost zero or
negative energy, but you don't know if it's expanding or
compressing space, but it is that if it is, and
you could use it to maybe make a warp drive maybe,
because we don't really even know if it counts as
negative energy density and a gravitational sense. Again, it's just
relatively lower energy than the rest of the vacuum. And
so in this paper, what they were doing was thinking

(40:19):
about the energy density from the Cassimir effect, and they
were doing a bunch of simulations. So in this paper
they didn't build anything right, They didn't like create a
lab and build something. They were just doing calculations on
the computer, thinking about what is the energy density between
objects that are really close together, thinking about the Cassimir effects.
That they were doing a bunch of calculations. So then
what did they find in their simulations and why do

(40:40):
people use that to make the headline that NASA created
a warp drive. So they were doing a bunch of
calculations and they saw a plot and I had these
funny shapes in it. And one person who's working on
the project is also really interested in warp drives and
remembers seeing a similar shape in a paper about warp drives,
and we said, oh, this figure here, this shape of
the energy density looks kind of like the shape you

(41:02):
would need for a warp drive. Well, maybe step us
through with more detail here. What is there's a plot
of just a plot of the energy density between two surfaces,
Like in the Casimer effect, you bring two surfaces very
close together and you get lower energy density between the
surfaces than around it. Again, that doesn't necessarily mean actually
negative energy density from a gr perspective, but had like

(41:24):
an interesting shape and it had sort of the same
shape as a figure from a warp drive paper. That said,
here's the negative energy density profile. You would need to
expand the space behind the warp bubble. So it just
sort of like, oh, we have a crescent in this plot.
We have a crescent in that plot. Maybe they're the
same thing, but they're not at all, right, It's just
sort of vaguely similar. And this is just a qualitative

(41:47):
comparison of two things that might not even be related.
It's just like saying, oh, the Casimir effect creates this
crescent shape negative energy density. I also have a cookie
of that shape, So maybe the Casimere effect makes cookies. Well,
who doesn't want to warp cookie? But what's a little
I feel like maybe it's a little bit more than that, right,
because you know what they saw in this simulation. It

(42:07):
seems like it is that if you bring these two
plates together and measure the Cassomer effect, you get a
dip in the energy between the two plates. Right, That's
probably what they saw, like a dip in the energy.
And if you plot the energy between the two plates,
you'll see a dip. And he's saying, well, to make
a warp train, you need to also kind of create
this dip in energy behind you. You certainly do, but

(42:28):
we don't know again if the Casomer affects relative decrease
in energy density would actually create the kind of expansion
of space we need for the work bubble, and the
work bubble needs to sort of general relativistic negative energy density,
which requires like particles of negative mass, for example, whereas
the Casimir effect creates a relative shift in the quantum

(42:49):
vacuum and we don't know the impact of that Gravitationally,
all this paper is doing is saying, oh, look, I
made a shape of relative decrease of energy density that's
similar to the actual negative energy density in a warp
bubble metric. Right, So then I guess what would be
the idea is that you somehow create a whole bunch
of these plates really close together behind you, and somehow

(43:10):
that decreases the density behind you and somehow that compressive space.
Is that kind of where they were going with this.
That's sort of where they were going with this. But
you know there's a lot of leaps there, right. First
of all, Number one, this is just a simulation. Haven't
built anything, haven't demonstrated that their calculations are correct. But
you said that Cassimer effect has been proven experimentally. Yeah,
the Casomer effect has been proven experimentally, but that doesn't

(43:31):
mean that everybody who's doing Casimir effect calculations is correct.
And this particular team has a bit of a spotty
history in publishing papers. This is the same team that
was working on the e M Drive, an attempt to
build a rocket that violates Newton's third law, you know,
propellant less rocket. So you know, you've got to take
everything they do with a bit of a grain of salt.
And they also haven't shown a really crucial step, which

(43:54):
is that the Casimir relative decrease in energy density actually
does provide the negative energy density you need for general
relativity to create this wark bubble. They just have not
shown that at all. So I passed this paper to
an expert in a friend of the podcast and Baroxter Scheney,
who's a professor of cosmology and gravitational physics, and his
review was, this paper is a pure nonsense. How this

(44:18):
paper passed pure review is completely beyond me harsh, I mean,
let's not mince words. It's a pure nonsense. That was
his evaluation. He was not very impressed with this paper. Well,
from a theoretical point of view. Yes, I feel like
from what I'm understanding here from you today is that, Yeah,

(44:38):
they skipped over the fact that we don't have confirmation
that lower energy leads to a expansion of space. But
everything seems to kind of point to that, right, that's
kind of how the universe works. More energy you have,
more space gets compressed, I suppose. But we don't know
how to do the calculations to predict the impact on
the curvature of space of lower quantum feel the energy.

(45:00):
Remember again that g R is a classical theory can't
handle quantum particles, not to mention infinite towers of virtual particles.
People have tried to do those calculations and gotten crazy
bonkers results, which suggests that what we need is a
new theory of quantum gravity that might let us do
this and it might work. Right. It might be that
the Casimir effect does decrease the local energy density in

(45:24):
such a way that a theory of quantum gravity would
predict the expansion of space in just the right way
to give you a warp bubble. But this paper doesn't
show that, right, It doesn't show that. But you know,
they're just presenting the results of their simulation and saying
there's maybe a link to war drive. Maybe the real
problem was that it got picked up by the media
and then the headline got over blown because if you
read the title of the paper, it's not like, hey,

(45:46):
we made a warp drive, it's how would here because
you sent to me worldline numerics applied to custom Casimir
geometry generates unanticipated intersection with al Kabir warp metric. Yes, absolutely,
the title their paper is much better than the title
of a Coffee or Die article that says that they
accidentally create warp bubble for interstellar travel. I completely agree.

(46:08):
And they have the word numerics here, so they are
saying that it is a simulation. Now, that's right. A
lot of the misunderstanding lies in the coverage of this paper.
This paper definitely doesn't show that NASA accidentally created a
warp bubble. It just shows that the Casimir effect in
certain configurations can generate decreases in local energy density to
have a similar shape qualitatively to what you would need

(46:31):
for a warp bubble. And again it's just qualitative. They
didn't even like analyze quantitatively to say like, is this
actually the shape they need? It just sort of like
looks the same on the page. Right, So then you
might say that NASA might have accidentally built the war drive. Well, also,
these guys aren't at NASA. Like nobody here works at NASA.
I mean most people who work in NASA to work
at NASA, right, They're not like working for NASA. This

(46:53):
is not a NASA funded study. This was a study
funded by DARPA, however, So that's where the headline made.
The mistake should have been the government might have accidentally
built a warp drive. Some people in a garage that
previously have made outrageous claims did a calculation that looks
to them on the screen similar to something they remember
being relevant to warp bubbles. Now you're being ours there.

(47:15):
I thought anyone could come up with a great idea.
Absolutely anybody can, are you say, anybody? If I work
at my garage, I can't come up with a good idea.
But though these people are at a university, right, some
of these folks are. Some of them are in the
engineering department at Texas and m which is near NASA.
Kind of right, If any two places in Texas are
adjacent to each other, then sure, maybe because they have

(47:35):
a warp drive ensuring that distance between spots in Texas.
Maybe they can't. And absolutely, you're right. Anybody could come
up with a great idea and it might be that
in somebody's garage one day a warp drive is built.
All right, Well, it sounds like the very date here
is that the science as it is is not super exaggerated, right,
because they are doing simulations and they are just saying

(47:57):
there is a qualitative connection there. But sounds like maybe
the headline that picked it up did overblow the implications
of it or the probability that it might be translated
into an actual warp drive. Yeah. I think that's a
generous reading of it. Yeah, we already know your harsh
reading of it and your friends. Well, let's hope that
somebody builds a warp train one day, and you know,

(48:20):
we have like a new character on Thomas the train,
we have like the warp engine. I think the conclusion
here is that maybe these websites that picked it up
warp reality a little bit. Yeah, and not accidentally, I imagine.
So be careful where you get your science news, but
feel free to send us any headline you see that
it makes you wonder or it gets you excited, We're
happy to digest it for you and give you a

(48:42):
sense for whether or not it's the next big breakthrough.
That's right, and we need tips on how to use
word to make their paper or a tax. You can
also email Daniel that's right. Send us your questions about
warp drives, about space physics, and about a tech two
questions at Daniel and Jorhea dot com. Have you enjoyed that?
Thanks for joining us, see you next time. Thanks for listening,

(49:11):
and remember that Daniel and Jorge Explain the Universe is
a production of I Heart Radio. For more podcast for
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